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  Run code with multiple files in the same main package in GoLang

To run a GoLang program, there needs to be a main() function defined. In some cases when developing some demo program which has multiple files and just wanna put them in the same main package and this folder is not in GOPATH, how to run the program? Let's say we have following folder structure where the main() function is defined in main.go. If you just run below command, it would fail to start to run the program and gives some error if some struct is defined in other files and being used. PS D...

   EXECUTABLE,GOLANG,MAIN PACKAGE,MULTIPLE FILE     2021-05-15 10:20:10

  Implement struct no copy in GoLang

There is some case where some of the struct in GoLang which is not meant to be copied. For example, sometimes a global configuration which should have only one version passed around the whole application and should not be copied and modified. In GoLang, there is no intuitive solution on preventing copying of struct. But there is still some way which can be leveraged to help prevent this while developing the code. The trick is to define some struct implementing sync.Locker interface and has this ...

   GO VET,NOCOPY,NO COPY     2020-09-04 22:24:58

  Can two new objects point to the same memory address in GoLang?

Do you have any idea what the output will be for below GoLang snippet? package main import ( "fmt" ) type obj struct{} func main() { a := &obj{} fmt.Printf("%p\n", a) c := &obj{} fmt.Printf("%p\n", c) fmt.Println(a == c) } Many people would think that a and c are two different object instances which have different memory addresses. Hence a == c will be false. But if you try to run the above program, you would see below output 0x5781c8 0x5781c8 true To get to know the reason wh...

   GO,GOLANG,VARIABLE ESCAPE,ZEROBASE     2019-04-06 01:19:52

  /dev/null and /dev/tty in Linux

In Linux, there are two special files /dev/null and /dev/tty. /dev/null will drop all the data written to it, i.e, when program writes data to this file, it means the program has completed the data write operation. But in  fact it does nothing, if you just want the status of a command but not the output of a command, this feature will be very useful. See below shell codes:     /> vi test_dev_null.sh        #!/bin/bash    if grep...

   Linux,/dev/null,/dev/tty     2013-03-04 02:23:23

  Push docker image to remote AWS ECR

With the popularity of distributed and large-scale systems, there are more and more adoptions of cloud services. One of the most popular container in the market is Docker and one of the most popular cloud service provider is AWS. From development perspective, there is frequent need to push local docker image to remote ECR for debugging or testing purpose. Normally when a code change is done and the committed change would go through a series of process like code review, push to remote repo, merge...

   CLOUD,AWS,DOCKER,AWS ECR     2020-12-13 04:12:26

  Useful git commands in daily work

In a developer's daily work, it is frequent to see lots of commits made. It would be a headache if one cannot use git commands well especially when in cases where some fixes need to be made on existing branches. There are some frequently used command such as git pull, git merge and git push. Apart from these, there are some other practical commands which may be useful for real use cases. This post will try to list some of them. git grep  It will lists all files containing the searched keywo...

   GIT,GIT COMMAND,GIT LOG     2022-05-01 03:17:15

  12 useful Chrome commands

Many useful features of Chrome don't show up on its menus. You can access them through the chrome:// command. In this article we will introduce 12 useful chrome:// commands. 1. chrome://flags It can be used to turn on or turn off some chrome features. 2. chrome://dns This command will show the domain name list caught by the browser. 3. chrome://downloads You can access this through chrome menu as well. The shortcut is Ctrl+J 4. chrome://extensions This command equals to Menu->Tools->Ext...

   Chrome,chrome://     2013-01-25 04:38:03

  Deep clone of JavaScript object

In JavaScript world, it's frequently seen object clone. Normally when creating a clone of an object, it's only the reference being cloned but not all contents. In some scenarioes, it's desired to clone all the content instead of just the reference such that any change made to the cloned object will not change the original object. Differences between shallow clone and deep clone can be as simple as: Shallow clone : Only the object reference is cloned but not the content Deep clone : Clone all co...

   JAAVSCRIPT,DEEP CLONE,DEEP COPY,SHALLOW CLONE,SHALLOW COPY     2016-10-31 00:27:24

  Remote execute command in Java example

Frequently there is a need to logon to a remote system and run some commands or programs to get the output, many software can serve this purpose such as putty and gitshell.These software usually provide secure access to the remote system. But have you ever wondered what to do if you need to run commands on many different systems at the same time and get all these results back at a single place? Especially in big data era, many tasks may run on different distributed systems and you want o have a ...

   JSch, Example, Distributed system, SSH2     2014-12-12 03:20:19

  Hide a file in a picture

Sometimes if you want to hide some important files on your computer which you don't want others to see, how would you do that? Find a professional tool? Set password for some folders? Change the file properties to hidden? They are possible, but they may not be so convenient or so secure. Here we share with you how to hide a file in a picture. Prerequisites 1 picture for example : test.jpg 1 test file, for example : test.txt WinRAR Steps Prepare the picture test.jpg and test file test.txt Use ...

   Trick,Picture,Fil hiding,WinRAR     2012-09-13 19:36:36